In modern information systems, a machine (e.g., a server machine) may manage a database in which one or more descriptors of an item are stored. An item may take the form of a good (e.g., a physical object), a service (e.g., performed by a service provider), information (e.g., digital media, such as an audio file, a video file, an image, or a document), a license (e.g., authorization to access something), or any suitable combination thereof. One or more descriptors that describe an item may be stored in the database managed by the machine.
The machine may form all or part of a network-based system that processes descriptors that describe one or more items. Examples of such network-based systems include commerce systems (e.g., shopping websites or auction websites), publication systems (e.g., classified advertisement websites), listing systems (e.g., wish list websites or gift registries), transaction systems (e.g., payment websites), and social network systems (e.g., Facebook®, Twitter®, or LinkedIn®).